1. Technical Field
This invention relates to the art of making light weight engine blocks, and more particularly to fluid cooled blocks requiring wet liners to define a water jacket.
2. Discussion of the Prior Art
In an effort to design light weight engine blocks, lighter weight metals, such as aluminum, have been formed into a shell for an iron-based liner structure, either two-piece or monoblock. It is desirable that the liner structure be exposed directly to cooling fluid to enhance thermal transfer. (See U.S. Pat. Nos. 4,446,906 and 4,759,317). These designs split the shell at conventional locations forming a joint between the crankcase chamber and the cooling chamber. If plastic or plastic composites were to be substituted for the exterior shell, cooling fluids containing chemicals that degrade sealing means over the life of the engine block would cause problems. Thus, the concept, such as presented in U.S. Pat. No. 4,446,827, would promote the possibility for contamination of engine oil within the crankcase chamber by leakage of coolant thereinto.
It is an object of this invention to provide a fluid cooled engine block that deploys light weight nonmetallic materials, such as plastic composites, for an outer shell of the water jacket without any risk of oil contamination by the cooling fluid.